Security readout for executives and security teams
Plain-English summary
CVE-2018-21176 is a post-authentication stack overflow in specific NETGEAR routers and gateways. An already authenticated user on an adjacent network could potentially compromise device confidentiality, integrity, and availability. Business urgency is moderate unless affected devices are internet-facing for management or exposed to untrusted local users.
Executive priority
Prioritize remediation for listed NETGEAR devices in business networks, especially branch, small office, and guest-access environments. This is not evidenced as actively exploited in the bundle, but affected perimeter or shared-network devices should not remain on vulnerable firmware.
Technical view
The source describes a stack-based buffer overflow affecting listed NETGEAR models before specific firmware versions. CVSS 3.0 is 6.8 with adjacent-network access, low complexity, high privileges required, no user interaction, and high impact across confidentiality, integrity, and availability. The bundle does not include CWE details or vulnerable endpoint specifics.
Likely exposure
Exposure is limited to the listed NETGEAR devices running firmware earlier than the named fixed versions. Risk is higher in networks where router administration is reachable from guest Wi-Fi, shared LANs, contractors, or other untrusted adjacent users.
Exploitation context
The provided sources do not state active exploitation, and KEV status is false. The flaw requires authentication with high privileges and adjacent-network access, which reduces opportunistic internet-scale risk but still matters for compromised admin credentials or hostile local network positions.
Researcher notes
The source bundle names affected models and fixed-version thresholds but lacks endpoint-level detail, CWE mapping, proof-of-concept status, and vendor mitigation text beyond the advisory reference. Treat impact conclusions as bounded by CVSS and vendor/CVE descriptions.
Mitigation direction
- Upgrade affected NETGEAR models to firmware at or above the listed fixed versions.
- Review the NETGEAR advisory before applying model-specific firmware updates.
- Restrict administrative access to trusted management networks only.
- Disable any unnecessary remote or untrusted management exposure.
- Rotate router administrator credentials if exposure or credential compromise is suspected.
Validation and detection
- Inventory deployed NETGEAR models and current firmware versions.
- Compare each device against the fixed firmware versions in the advisory.
- Verify administrative interfaces are unreachable from guest or untrusted network segments.
- Confirm firmware update completion through approved device management records.
- Document exceptions where devices cannot be upgraded immediately.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2018-21176 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:H/S:U/UI:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:H/S:U/UI:N0.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
6.8MediumVector: CVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:H/S:U/UI:N
Source materials
- CVE List V5 sourceCVE List V5
- https://kb.netgear.com/000055182/Security-Advisory-for-Post-Authentication-Stack-Overflow-on-Some-Routers-and-Gateways-PSV-2017-2623CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.